A method for controlling performance of an MCM capable support surface having a flowpath for guiding a stream of air along at least a portion of the surface, comprises specifying a desired evaporative rate greater than an evaporative rate achievable with unconditioned ambient air, chilling the unconditioned ambient air to a temperature at least as low as that required to achieve 100% relative humidity, thereby demoisturizing the air, and supplying the chilled, demoisturized air to the flowpath. The method may also include the step of heating the chilled, demoisturized air prior to step of supplying it to the flowpath. A system for carrying out the method includes a microclimate management (MCM) capable support surface 22, a chiller 60 for cooling air to be delivered to the MCM capable surface, a user interface 42 for receiving instructions concerning desired microclimate management performance, and a controller 50, responsive to the instructions, for operating the chiller.